Certified Rhythm Analysis Technician (CRAT) Practice Exam

The characteristic that differentiates atrial flutter from other atrial dysrhythmias is the "saw tooth" or "picket fence" appearance of waveforms before the QRS complex. This distinct pattern is often referred to as "F-waves," and it typically occurs in a regular rhythm, giving it a unique visual representation on an ECG. In atrial flutter, these waves are usually consistent in appearance and can be identified in the context of a specific atrial rate, commonly around 240 to 340 beats per minute. This reliable morphology is a key identifier for clinicians when diagnosing atrial flutter, setting it apart from other conditions characterized by different waveforms or irregular rhythms.

Other options reflect features that can be found in other atrial dysrhythmias. For instance, fibrillatory waves are characteristic of atrial fibrillation rather than flutter. Delta waves before QRS complexes are primarily associated with Wolff-Parkinson-White syndrome, and varying sizes and amplitudes of P waves are indicative of conditions such as multifocal atrial tachycardia. Thus, the "saw tooth" pattern is a hallmark feature specific to atrial flutter.